The latest interview with Game Watch that Reinheart kindly translated. It's a long one. Important bits regarding the latency are in the second half of the interview. Basically this bit:
GW: I forgot how long ago but when I started playing FFXIV I checked the Ping to Square-Enixs server. (Laugh) reason why was because I had experience of being pushed off the edge with land slide from Titan Hard Mode, I was thinking to myself “I dodged that for sure, why!” and that’s when I checked, at that time I was using the smart phones tethering to play. So when I checked it was slow. Went back home and checked again and the Ping was in the one digit and was easy to dodge. The previous FFXIV’s server lag was really horrible, but for FFXIV ARR for the lags it’s most likely a problem with the local side environment. However, there are many out there that claim it’s the game sides issue and it’s hard.
Yoshida: I can’t talk about that from my end so please do so from GAME Watch’s side (laugh).
GW: It’s really simple matter, if you can just release ping check tool to game server it will resolve this issue.
Yoshida: It’s not so easy to add that officiallly when there are several ISP’s involved.
GW: But, since we all know the IP it’s possible to add it in the benchmark program to show when players check the PC performance so they can understand the issue. I really think the current situation is unfair. People still mentioning it even after FFXIV ARRs launch must mean that there are that much people that is misunderstanding.
Yoshida: What I can official say from my end is that if you’re really going to fully go into the contents please have the best environment. But this is really hard, there are those that will say “You are the one creating the Online Game, you prepare that type of environment”, or look over it and make adjustments so you can dodge those.
GW: That’s impossible.
Yoshida: It is, if we do that we can’t make difficult contents.
GW: If you’re able to dodge with 3 digit Ping then it’s not fun as a game
Yoshida: We would need to extend the time players have to dodge. But doing that will make the content super easy, so it’s impossible.